Raffaele Amato has been a fugitive from Italian justice since 2006
An alleged leader of the powerful Neapolitan-based mafia, the Camorra, has been arrested in southern Spain, Italian prosecutors have said.
Raffaele Amato was detained in a joint operation by Italian and Spanish police in the city of Marbella on Saturday.
Mr Amato is accused of eight murders between 1991 and 1993, and of being "the principal, or one of the principal importers of cocaine into Italy".
He had been living under a false name on the Costa del Sol, police said.
The 44-year-old had been a fugitive from Italian justice since 2006, when a Naples court issued a warrant for his arrest for murder.
Police said Mr Amato had once been a key lieutenant of the alleged mafia godfather, Paolo Di Lauro, who was sentenced to 30 years in prison in 2006 for Mafia association, extortion and drug trafficking.
However, about five years ago he led a successful breakaway from Di Lauro and took control of the narcotics market in Naples, they added.